Investigating temperature influences on shell growth and microstructural variations in bay scallops: insights from...

Area of Science:

• Marine Biology
• Biomineralization
• Climate Change Ecology

Background:

• Scallops (Pectinida) possess robust calcitic shells influenced by environmental factors like temperature.
• The bay scallop (Argopecten irradians) is ecologically and aquaculturally significant, with potential range expansion due to global warming.
• Understanding temperature effects on shell accretion and microstructure is crucial for predicting climate change impacts.

Purpose of the Study:

• To investigate the impact of elevated water temperature on bay scallop shell accretion rate.
• To analyze the effect of water temperature on the polycrystalline microstructure of bay scallop shells.
• To assess the influence of temperature on shell mechanical properties.

Main Methods:

• Controlled growth experiment with juvenile bay scallops reared at 23 °C and 26 °C for 9 weeks.
• Fluorescent staining (calcein) for accretion rate assessment and micro-computed X-ray tomography for 3D morphologic characterization.
• Mechanical testing (compression) and microstructural analysis (SEM, EBSD) of scallop shells.

Main Results:

• Scallops reared at warmer temperatures (26 °C) exhibited significantly faster shell accretion rates.
• Warmer water resulted in shells with higher calcite grain misorientation, indicating microstructural changes.
• No significant differences were found in relative shell thickness, stiffness, strength, or toughness.

Conclusions:

• Elevated water temperatures promote faster shell growth in bay scallops.
• Temperature-induced microstructural changes (increased grain misorientation) occur without compromising overall shell thickness or mechanical integrity.
• Findings provide insights into the potential biological responses of scallops to climate change and ocean warming.